The present invention concerns a device for lifting, in particular in the event of a breakdown of failure, the ban on the opening of a conditional opening locking system.
More particularly, the invention relates to the application of this device to a high security time-lock locking system, for controlling, over determined periods of time, access to high security enclosures, such as for example bank safes and strongrooms.
Such a device and time-lock locking system of this type are described in EP Patent No 0 256 430 (corresponding to U.S. Pat. No. 4,944,170-Jolidon et. al).
A security mechanism described in this Patent Document and incorporating this device and locking system, is shown very schematically in FIG. 1.
As described in this Patent Document and as shown in this Figure, the locking of a door PO of a safe or any other high security enclosure (this door being seen from inside in FIG. 1), is generally made, via several bolts or latch bolts PT controlled by a rod assembly TR, said rod assembly being able to be moved, by an operator, via a hand wheel VO, from a latching position to an unlatched position and vice versa.
Rod assembly includes for this purpose a bar B which controls the movement of bolts PT of door PO and which is coupled to hand wheel VO, via a mechanism of the rack and pinion type.
This bar B can be moved, in translation, by the action of hand wheel VO, to order the movement of bolts PT and to assure the latching (bolts withdrawn) and unlatching (bolts pushed in) operations.
In order to prevent the unlocking of door PO and hold rod assembly TR in the latching position when bolts PT are in this position, this assembly includes a first lock S which is itself provided with a bolt PS provided for engaging in bar B. Bolt PS is thus provided for blocking the translation movement of bar B.
This first lock S can be controlled, in the simplest version by a key, or even by more sophisticated means, such as a magnetic card, a smart card or an electronic system operating with a code or any other type of access authorization.
However, in order to raise the level of security and to prevent any fraudulent use of this first lock S, a second lock SH called the time lock is associated therewith.
This time lock SH also includes its own bolt PV, which is called more generally a latch or blocking member and which is provided for being placed on the path of bar B, in order to impede the movement thereof into its unlatched position. In the raised position of blocking member PV shown in FIG. 1, bar B thus abuts member PV with its rear end.
Blocking member PV is associated, in this time lock SH, with a driving assembly EM, including in particular an electromagnetic motor and a cam and lever mechanism (not shown).
This driving assembly EM can be controlled by electronic means EL associated with peripheral display means PA and data input means ED used for programming the periods of time. Peripheral means PA and ED are formed, in this example, by a digital display and a keyboard. Electronic means EL include a microprocessor MP and a memory MM of the RAM/ROM type, microprocessor MP providing, from the program stored in memory MM, control signals which pass via an amplifier AMP, to driving assembly EM.
Thus, via this arrangement, it is possible to program periods of time during which blocking member PV will prevent the sliding of bar B, even if a valid authorization signal orders the opening of the first lock S, i.e. by a key or another known opening code.
Consequently, by using this time lock SH, security is doubled, by preventing any unlocking of the safe or enclosure during one or more judiciously selected time periods, even by authorised personnel in possession of a key or another valid code.
However, if, after such a period of &lt;&lt; ban on opening &gt;&gt;, the ban command is unintentionally maintained by a mechanical or electronic malfunction of the time lock, the opening of the door is, in this case, completely impossible, since blocking member PV of time lock SH physically impedes movement of bar B of the rod assembly.
This time lock SH and this blocking member PV are designed and positioned on door PO to be inviolable, thus inaccessible and indestructible, which prevents, a priori, even in this exceptional situation, any access and any reparation even by security teams.
Such malfunctions can be caused, either by failure, or by a breakdown in the electronics and/or the motor driving the blocking member.
Consequently, in order to have access to the protected enclosure, such malfunctions require that the enclosure is destroyed by breaching, for example the wall or a side of the enclosure, or by destroying the door.
In any event, it is necessary to damage the security enclosure, which is excessively expensive.
Moreover, in order to be able to breach such enclosure or to destroy the door, very specialised services or tools are required, which is also expensive.
Furthermore, these operations can require several hours or even days to be achieved. During this time, it is unfortunately not possible to have access to the interior of the enclosure to satisfy clients, in particular in the case of a bank.
Next and most of all, once the enclosure has been damaged, it must be repaired, so that the enclosure cannot be used during a certain period of time, i.e. for several days or weeks. This situation can be very detrimental in many applications.
For these reasons, it has been proposesd to associate with these time locks, a device allowing, via a special procedure, the operation of the time lock to be prohibited in the event of a breakdown or failure, in order to authorise movement of bar B of rod assembly TR and to allow the opening of door PO.
This type of device thus allows the time ban on opening imposed by time lock SH to be lifted.
A device of his type is also disclosed in the above mentioned EP Patent No 0 256 430.
In order to better grasp the structure of this device, the latter has also been shown very schematically in FIGS. 2a to 2f, in its characteristic operating positions.
This device D includes a lever 1 which can pivot and which is provided for co-operating with a beak 2 mounted on a barrel 4. Lever 1 can, in addition, co-operate with a stud G attached to blocking member PV which, in the position shown in FIG. 2a, is in the raised position for blocking bar B. It will be noted that blocking member PV is held in this position by a compression spring R which is supported by a stem TG driven by driving assembly EM (FIG. 1).
In this normal operating position, blocking member PV prevents movement of bar B, so that the door of the enclosure cannot be opened.
As is seen in FIG. 2b, member PV can be brought downwards, by lowering stem TG (arrow F1), by the action of driving assembly EM, to release the path of bar B and allow the door to be opened. In this lowered position of member PV, bar B can be withdrawn (arrow F2), in order to release bolts PT of rod assembly TR.
It is thus seen that in this operating mode, lever 1 and barrel 4 are not operative and they have no effect on the normal operation of time lock SH.
Barrel 4 carries a dowel-pin 6 which is associated with another prestressed compression spring, not shown; this assembly being housed in a blind hole arranged in barrel 4.
In the event of a breakdown or failure, an electronic circuit CE which is associated with a set of sensors, detects the failure and controls a second not shown driving assembly, which drives barrel 4 in rotation (FIG. 2c, arrow F3), via a gear train and a spring (not shown), this spring being provided for storing the driving energy provided by this driving assembly.
If bar B is in the position abutting blocking member PV (FIG. 2c), beak 2 will then abut bar B, the spring which drives barrel 4 then absorbing the driving energy provided by the corresponding driving assembly.
If after lock S has opened, the operator notes a malfunction of time lock SH, he moves bar B to its latching position, via the control hand wheel (FIG. 2d, arrow F4). Barrel 4 can then continue its rotation (arrow F5) to come to stop against a fixed stop 8.
In this position, dowel-pin 6 will engage in a recess 9 arranged in lever 1, which mechanically and irreversibly connects or couples barrel 4 to lever 1.
Since beak 2 is now in this position on the path of bar B, the operator by withdrawing this bar (FIGS. 2e and 2f, arrow F6) will push beak 2 which causes the rotation of barrel 4.
Thus, barrel 4 which is now connected in rotation to lever 1 via engagement of dowel-pin 6 in recess 9, causes lever 1 to pivot which will push stud G of blocking member PV (FIG. 2e), against the effect of spring R. It will be understood that because of the state of malfunction, stem TG has remained in the raised position and continues to push spring R against blocking member PV. Lever 1 will thus oppose the return force of spring R which is compressed.
Thus, by continuing to move bar towards its unlatched position, the operator can cause the release of member PV by retracting completely, due to lever 1 (FIG. 2f, arrow F7). The door can thus be opened.
This device allows the desired result to be obtained.
However, it has several drawbacks.
In order to set time lock SH and device D in operation again, barrel 4 must be separated from lever 1 and lever 1 must be brought into its initial rest position. This operation necessitates opening the lock and requires the intervention of a specialist, such intervention possibly requiring several days. During this time, the time lock is out of operation.
Moreover, given that it is the movement of bar B which allows the lock to be &lt;&lt;forced &gt;&gt; open, distinct batches of adapted locks must be provided, either for left opening doors (configuration shown in FIGS. 2a to 2f), or for right opening doors (not shown symmetrical configuration). This condition thus imposes manufacturing, assembly, administration and logistics for two types of locks, which increases the lock cost price.
Furthermore, these locks must be subjected to very precise adjustment during assembly, since bar B absolutely must come into contact with beak 2, to assure proper operation of the rescue lock.
In addition, the parts which form ban lifting device D must be of high quality. They must be able to overcome the force of compression spring R which tends to hold blocking member PV in its raised position.
Consequently, this device implements a significant number of parts which are difficult to make and adjust, so that it is relatively uneconomical.